Charles "Chad" Ludington, who now teaches at North Carolina State University, said he was a friend of Kavanaugh's at Yale and that Kavanaugh was "a frequent drinker, and a heavy drinker."

WASHINGTON (AP) — Democrats are raising new questions about the truthfulness of Brett Kavanaugh’s sworn testimony to the Senate, shifting tactics against President Donald Trump’s Supreme Court nominee as they await the results of the FBI’s background investigation into sexual misconduct allegations.

Chuck Schumer, the Senate Democrats’ leader from New York, accused Kavanaugh of delivering a “partisan screed” during the Judiciary Committee hearing last week. He said Kavanaugh seemed willing to “mislead senators about everything from the momentous to the mundane” to ensure his ascension to the high court.

“The harsh fact of the matter is that we have mounting evidence that Judge Kavanaugh is just not credible,” Schumer said Monday.

Not so, argued Senate Republican leader Mitch McConnell of Kentucky, contending the Democrats are simply looking to “move the goalposts” to prevent Kavanaugh’s confirmation. He pledged that the full Senate would begin voting on Kavanaugh’s nomination this week.

“The time for endless delay and obstruction has come to a close,” he said.

Kavanaugh’s confirmation hinges on a handful of key Republican and Democratic senators who have not yet fully tipped their votes. One of them is Republican Jeff Flake of Arizona, who was greeted by hundreds of liberal protesters, victims of sexual assault among them, during an appearance Monday in Boston.

Flake and Sens. Susan Collins of Maine and Lisa Murkowski of Alaska were instrumental last week in holding up Kavanaugh’s confirmation vote. They forced the White House to open a supplemental background investigation of sexual misconduct allegations against the judge.

The votes of the three Republicans and those of red-state Democrats Joe Manchin of West Virginia and Heidi Heitkamp of North Dakota will largely determine whether Kavanaugh is confirmed.

Flake said he would ensure it’s a “real investigation,” by the FBI as Democrats demanded that Trump give them a full readout of his instructions to the agency.

“It does us no good to have an investigation that just gives us more cover,” Flake said.

Heitkamp, meanwhile, noted that Trump himself called for a “broader” FBI investigation into the allegations. She said, “I’m waiting to see what the results are.”

Kavanaugh has emphatically denied Christine Blasey Ford’s allegation that he sexually assaulted her at a gathering when they were teens. He has also denied an accusation from Deborah Ramirez, a classmate at Yale, who said he exposed himself to her at a dorm party more than 25 years ago. A third claim — from Julia Swetnick, who is represented by attorney Michael Avenatti — accuses Kavanaugh of excessive drinking and inappropriate treatment of women at parties in the early 1980s. Kavanaugh denies that as well.

Democrats have seized most recently on Kavanaugh’s indignant, emotional testimony before the Judiciary Committee to question whether he has the temperament for a lifetime appointment on the nation’s highest court.

In particular, Democrats have homed in on his contention that the allegations against him are an “orchestrated political hit” funded by left-wing groups seeking “revenge on behalf of the Clintons.”

Sen. Mazie Hirono, a Democrat from Hawaii, said, “We’re going to put a conspiracy theory believer on the court?”

Democrats are also questioning Kavanaugh’s honesty, particularly over statements he made about his drinking in high school and college.

Kavanaugh testified that while he enjoys drinking beer, and often did so in high school, he never drank to excess. He lashed out at senators who asked if he had ever blacked out. In one notable exchange, he snapped at Sen. Amy Klobuchar, D-Minn., “Have you?”

Schumer said Kavanaugh was “rudely interrupting” senators in a way he’d never seen from a witness.

Former classmates have stepped forward to challenge Kavanaugh’s testimony about his drinking. Charles “Chad” Ludington, who said he was a friend of Kavanaugh’s at Yale University and now teaches at North Carolina State University, called Kavanaugh “a frequent drinker, and a heavy drinker.” But the White House released statements from two other Yale classmates Monday who said they never saw Kavanaugh black out or treat women with disrespect.

Pushing back on the Democratic attacks, Republicans said Kavanaugh had every right to be upset during the hearing.

McConnell mocked the questions from Democrats about Kavanaugh’s drinking in high school and college. He said Kavanaugh was “rightfully angry” about the accusations, and he added, “Who wouldn’t be?”

Sen. John Kennedy of Louisiana, a Republican member of the Judiciary Committee, said Kavanaugh has only been responding to Democratic attacks.

“He’s on trial for his life, so is his spouse, so are his parents, so are his kids, and he got mad. Now they are criticizing him for getting mad. I think that’s the height of hypocrisy.”

The FBI is expected to spend the coming days investigating the sexual misconduct claims against Kavanaugh. Senators have said they want the investigation completed by Friday.

Democratic Sen. Chris Coons said after speaking with White House counsel Don McGahn over the weekend he remained “very concerned” the FBI’s probe would be too narrow.

Responding to those concerns, Trump said at a press conference he wants the FBI to do a “comprehensive” investigation and “it wouldn’t bother me at all” if agents pursued accusations made by the three women. But he also said Senate Republicans are determining the parameters of the investigation and “ultimately, they’re making the judgment.”

“My White House will do whatever the senators want,” Trump said. “The one thing I want is speed.”

Still, Trump slammed Senate Democrats during a campaign rally in Tennessee Monday night. “If we took 10 years, they’d want more time,” he groused.